Adjustable bed frames are available in many forms. Mechanisms used to elevate and lower the bed frames include electro-mechanical, pneumatic, cable and pulley, and various devices involving a variety of mechanical linkages. In general, the structures include a main support and a pair of mechanisms located at the respective head and foot ends of the main support. The mechanisms are operable to change the elevation of the main support and in some cases to change the longitudinal orientation of the main support relative to horizontal. Such structures are often complicated require mechanical interconnection between the mechanisms to ensure that during elevation the main support is maintained in a fixed relationship to the horizontal.
The present invention is intended to provide an adjustable bed frame capable of being lowered as close to a support surface as possible while providing access under the bed frame for the feet of a patient lifting device and also maintaining the option of elevating the bed fame into a normal position for use.